
#include "antsUtilities.h"
#include <algorithm>

#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"

#include "itkImageRegionIteratorWithIndex.h"

#include <string>
#include <vector>

namespace ants
{

template <unsigned int ImageDimension>
int PasteImageIntoImage( unsigned int argc, char *argv[] )
{
  using PixelType = float;
  using ImageType = itk::Image<PixelType, ImageDimension>;

  std::vector<unsigned int> startIndex =
    ConvertVector<unsigned int>( std::string( argv[5] ) );

  using ReaderType = itk::ImageFileReader<ImageType>;
  typename ReaderType::Pointer reader1 = ReaderType::New();
  reader1->SetFileName( argv[2] );
  reader1->Update();

  typename ReaderType::Pointer reader2 = ReaderType::New();
  reader2->SetFileName( argv[3] );
  reader2->Update();

  PixelType backgroundValue = 0;
  if( argc > 6 )
    {
    backgroundValue = static_cast<PixelType>( atof( argv[6] ) );
    }
  bool writeOver = true;
  if( argc > 7 )
    {
    writeOver = static_cast<bool>( std::stoi( argv[7] ) );
    }
  PixelType conflictLabel = -1;
  if( argc > 8 )
    {
    conflictLabel = static_cast<PixelType>( atof( argv[8] ) );
    }

  itk::ImageRegionIteratorWithIndex<ImageType> It(
    reader2->GetOutput(), reader2->GetOutput()->GetLargestPossibleRegion() );
  for( It.GoToBegin(); !It.IsAtEnd(); ++It )
    {
    typename ImageType::IndexType index = It.GetIndex();
    PixelType paintValue = It.Get();
    for( unsigned int d = 0; d < ImageDimension; d++ )
      {
      index[d] += startIndex[d];
      }
    if( ! itk::Math::FloatAlmostEqual( paintValue, backgroundValue ) )
      {
      if( reader1->GetOutput()->GetLargestPossibleRegion().IsInside( index ) )
        {
        PixelType canvasValue = reader1->GetOutput()->GetPixel( index );
        if( itk::Math::FloatAlmostEqual( canvasValue, backgroundValue ) || writeOver )
          {
          reader1->GetOutput()->SetPixel( index, paintValue );
          }
        else if( ! itk::Math::FloatAlmostEqual( canvasValue, backgroundValue ) && ! writeOver )
          {
          continue;
          }
        else
          {
          reader1->GetOutput()->SetPixel( index, conflictLabel );
          }
        }
      }
    }

  using WriterType = itk::ImageFileWriter<ImageType>;
  typename WriterType::Pointer writer = WriterType::New();
  writer->SetFileName( argv[4] );
  writer->SetInput( reader1->GetOutput() );
  writer->Update();

  return EXIT_SUCCESS;
}

// entry point for the library; parameter 'args' is equivalent to 'argv' in (argc,argv) of commandline parameters to
// 'main()'
int PasteImageIntoImage( std::vector<std::string> args, std::ostream* /*out_stream = nullptr */ )
{
  // put the arguments coming in as 'args' into standard (argc,argv) format;
  // 'args' doesn't have the command name as first, argument, so add it manually;
  // 'args' may have adjacent arguments concatenated into one argument,
  // which the parser should handle
  args.insert( args.begin(), "PasteImageIntoImage" );

  int     argc = args.size();
  char* * argv = new char *[args.size() + 1];
  for( unsigned int i = 0; i < args.size(); ++i )
    {
    // allocate space for the string plus a null character
    argv[i] = new char[args[i].length() + 1];
    std::strncpy( argv[i], args[i].c_str(), args[i].length() );
    // place the null character in the end
    argv[i][args[i].length()] = '\0';
    }
  argv[argc] = nullptr;
  // class to automatically cleanup argv upon destruction
  class Cleanup_argv
  {
public:
    Cleanup_argv( char* * argv_, int argc_plus_one_ ) : argv( argv_ ), argc_plus_one( argc_plus_one_ )
    {
    }

    ~Cleanup_argv()
    {
      for( unsigned int i = 0; i < argc_plus_one; ++i )
        {
        delete[] argv[i];
        }
      delete[] argv;
    }

private:
    char* *      argv;
    unsigned int argc_plus_one;
  };
  Cleanup_argv cleanup_argv( argv, argc + 1 );

  // antscout->set_stream( out_stream );

  if( argc < 6 )
    {
    std::cout << argv[0] << " imageDimension inputCanvasImage inputImage "
             << "outputImage startIndex [backgroundLabel=0] [paintOverNonBackgroundVoxels=0] [conflictLabel=-1]"
             << std::endl;
    std::cout
      <<
      "   If the current painting image voxel is nonbackground and corresponds to a background voxel in the canvas image "
      << std::endl;
    std::cout << "     paintOverNonBackgroundVoxels = 0 -> leave the canvas voxel as is." << std::endl;
    std::cout
      << "     paintOverNonBackgroundVoxels = 1 -> replace canvas voxel value with painting image voxel value"
      << std::endl;
    std::cout << "     paintOverNonBackgroundVoxels = 2 -> replace canvas voxel walue with conflictLabel"  << std::endl;

    if( argc >= 2 &&
        ( std::string( argv[1] ) == std::string("--help") || std::string( argv[1] ) == std::string("-h") ) )
      {
      return EXIT_SUCCESS;
      }
    return EXIT_FAILURE;
    }

  switch( std::stoi( argv[1] ) )
    {
    case 2:
      {
      return PasteImageIntoImage<2>( argc, argv );
      }
      break;
    case 3:
      {
      return PasteImageIntoImage<3>( argc, argv );
      }
      break;
    case 4:
      {
      return PasteImageIntoImage<4>( argc, argv );
      }
      break;
    default:
      std::cout << "Unsupported dimension" << std::endl;
      return EXIT_FAILURE;
    }
  return EXIT_SUCCESS;
}
} // namespace ants
